Biology · Lesson Worlds
Selection: interactive science lab
Change how sooty the bark is and prove that the moths that match the tree are the ones that remain.
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What will you learn?
Natural selection keeps the traits that hide. On dark bark, dark moths remain. On pale bark, pale moths remain.
How does the lab work?
Observe the simulation, make a prediction, change a variable, run the experiment, and explain the result. Finish with a challenge that tests your understanding.
You can change: Soot. Compare what happens and connect the result to the scientific explanation.
Try a comparison in Selection
Start with the lab’s initial settings. Choose one control below, predict the result, and change that control while keeping the others fixed. Record the setting and what you observe before making a second change.
- Soot: the lab starts at 0.2; its available range is 0–1.
For a named starting condition, try Pale, Room, Dark. A preset can change several settings: check the controls before treating two presets as a one-variable comparison.
Questions to discuss during the activity
- Watch what happens. The light ones are hard to see. Watch moths on pale bark.
- Name the cause. Birds eat the moths they can see. If the bark darkens, light moths stand out and dark moths hide. The flock’s color shifts without anyone choosing it — the tree did the choosing. The tree is a filter.
- Change something. Darken the bark and dark moths should remain. Change soot, then wait.
- Guess before you run. If we raise soot to 0.85, the remaining moths will be… Guess what will happen, then run to check.
After your comparison, explain how the observations connect to this idea: Natural selection keeps the traits that hide. On dark bark, dark moths remain. On pale bark, pale moths remain. Name one condition you held fixed and one feature of the real world this model simplifies. A completed run is a starting point for discussion, rather than proof of mastery.
Who is it for?
Curious learners exploring biology. A parent or teacher can help younger learners read the instructions and discuss the results. Choose by topic and prior knowledge rather than a fixed grade level.
Is this lab free?
Yes. This interactive lab is free without signing in or a paid membership.
No app download is needed; interactive play requires JavaScript and a modern browser.
Use this activity with a learner
Families and educators · choose by prior knowledge
Learning goal: Natural selection keeps the traits that hide. On dark bark, dark moths remain. On pale bark, pale moths remain.
Before you begin: Read the controls for Soot. Make one prediction before changing a setting.
Check understanding: Ask for one observation, the evidence that supports it, and a question to investigate next.
A simulation simplifies the real world. Explain which conditions stayed fixed; a successful run alone does not demonstrate mastery.
Share Selection with your family or class. No account is needed to open the free resource.
Activity and guide by Lesson Worlds. About the platform.
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